208 The Palacontological Record. II. Plants 
since the discovery of the bisexual flowers of the Bennettiteae, 
have expressed different, views as to the nearness of their relation 
to the higher Flowering Plants, but the points of agreement are 
so many that it is difficult to resist the conviction that a real 
relation exists, and that the ancestry of the Angiosperms, so long 
shrouded in complete obscurity, is to be sought among the great 
plexus of Cycad-like plants which dominated the flora of the world 
in Mesozoic times}. 
The great complexity of the Bennettitean flower, the earliest 
known fructification to which the word “flower” can be applied 
without forcing the sense, renders it probable, as Wieland and 
others have pointed out, that the evolution of the flower in 
Angiosperms has consisted essentially in a process of reduction, 
and that the simplest forms of flower are not to be regarded as the 
most primitive. The older morphologists generally took the view 
that such simple flowers were to be explained as reductions from 
a more perfect type, and this opinion, though abandoned by many 
later writers, appears likely to be true when we consider the elabora- 
tion of floral structure attained among the Mesozoic Cycadophyta, 
which preceded the Angiosperms in evolution. 
If, as now seems probable, the Angiosperms were derived from 
ancestors allied to the Cycads, it would naturally follow that the 
Dicotyledons were first evolved, for their structure has most in 
common with that of the Cycadophyta. We should then have to 
regard the Monocotyledons as a side-line, diverging probably at a 
very early stage from the main dicotyledonous stock, a view which 
many botanists have maintained, of late, on other grounds*. So far, 
however, as the palaeontological record shows, the Monocotyledons 
were little if at all later in their appearance than the Dicotyledons, 
though always subordinate in numbers. The typical and beautifully 
preserved Palm-wood from Cretaceous rocks is striking evidence 
of the early evolution of a characteristic monocotyledonous family. 
It must be admitted that the whole question of the evolution of 
Monocotyledons remains to be solved. 
Accepting, provisionally, the theory of the cycadophytic origin 
of Angiosperms, it is interesting to see to what further conclusions’ 
we are led. The Bennettiteae, at any rate, were still at the gym- 
nospermous level as regards their pollination, for the exposed 
1 On this subject see, in addition to Wieland’s great work above cited, F. W. Oliver, 
‘‘Pteridosperms and Angiosperms,”’ New Phytologist, Vol. v. 1906; D. H. Scott, ‘The 
Flowering Plants of the Mesozoic Age in the Light of Recent Discoveries,” Journal R. 
Microscop. Soc. 1907, and especially E, A. N. Arber and J. Parkin, “On the Origin of Angio- 
sperms,” Journal Linn. Soc. (Bot.) Vol. xxxvm1. p. 29, 1907. 
2 See especially Ethel Sargant, “The Reconstruction of a Race of Primitive Angio- 
sperms,” Annals of Botany, Vol. xx. p, 121, 1908. 
